Superoxide Radical and Superoxide Dismutases: Threat and Defense
Authors:
- 1 January 1980
- book chapter
- Published by Springer Nature
- Vol. 492, 429-446
Abstract
An enzymic flux of O 2 − and H2O2 caused strand breaks in the supercoiled covalently closed circular Col El plasmid. Subnanomolar levels of superoxide dismutase or of catalase prevented this attack on DNA, signifying that both O 2 − and H2O2 were required. Benzoate, mannitol or histidine, which do not scavenge O 2 − and H2O2, also protected the DNA, suggesting that the proximate attacking species had a reactivity comparable to that of the hydroxyl radical. Replacing EDTA with diethylene triamine pentaacetic acid eliminated this attack. In toto the data suggest a metal-catalyzed interaction between O 2 − and H2O2 which generates a potent oxidant, possibly OH·, which can cause DNA strand scission. The biological implications of the production and the enzymic scavenging of the superoxide radical are discussed.Keywords
This publication has 34 references indexed in Scilit:
- Paraquat and the exacerbation of oxygen toxicityTrends in Biochemical Sciences, 1979
- The role of the superoxide anion in the xanthine oxidase-induced autoxidation of linoleic acidBiochemical and Biophysical Research Communications, 1978
- The mechanism of the bleomycin-induced cleavage of DNABiochemical and Biophysical Research Communications, 1977
- The protective action of superoxide dismutase on metal-ion catalysed peroxidation of phospholipidsBiochemical and Biophysical Research Communications, 1977
- Superoxide dismutase from Bacillus stearothermophilus. preparation of stable apoprotein and reconstitution of fully active Mn enzymeJournal of Molecular Biology, 1976
- Effects of superoxide radicals on myoblast growth and differentiationBiochemical and Biophysical Research Communications, 1974
- Biological protection by superoxide dismutaseBiochemical and Biophysical Research Communications, 1973
- On the formation of the superoxide anion radical during the reaction of reduced iron-sulfur proteins with oxygenBiochemical and Biophysical Research Communications, 1969
- Direct demonstration of superoxide anion production during the oxidation of reduced flavin and of its catalytic decomposition by erythrocupreinBiochemical and Biophysical Research Communications, 1969
- The production of superoxide anion radicals in the reaction of reduced flavins and flavoproteins with molecular oxygenBiochemical and Biophysical Research Communications, 1969